We can understand your misery when you forget your glasses at home and have to endure blurry vision in public. Check out this trick and save your eyes from straining while reading a menu or a text on your phone.
Make a hand fist and then open it just enough to create a tiny hole. Now look through the hole and you can see anything without the need for glasses. You may look weird peering on a book with the fist but it is better than blurry vision.
The science behind this trick is simple. The hand fist limits the light to the eyeball and increase focus i.e. the light is coming through from one place and one direction only which is why there is no blur. On the other hand, when you do not see through hand fist, eyes’ lenses focus spread out and eye muscles squeeze to focus at different distances.
Pinholes use the same principle but they did not correct the vision full-time and limit the peripheral vision. Therefore, glasses and contact lenses were invented.
Check out Minute Physics video below for more information.